Macro hashset

macro_rules! hashset {
    (@single $($x:tt)*) => { ... };
    (@count $($rest:expr),*) => { ... };
    ($($key:expr,)+) => { ... };
    ($($key:expr),*) => { ... };
}

Create a HashSet from a list of elements.

Example

#[macro_use] extern crate maplit;

let set = hashset!{"a", "b"};
assert!(set.contains("a"));
assert!(set.contains("b"));
assert!(!set.contains("c"));